Intervention and follow-up Patients randomized to citalopram will receive oral treatment with 20 mg tablets (10 mg if age ≥65 and/or reduced liver function) for 6 months with telephone contact after 2 weeks and 3 months and follow-up visits at 1 and 6 months. If patients develop depression dosage is initially doubled, followed by an additional control to evaluate effect and, if necessary, shifted to open-label antidepressant treatment. After 6 months, treatment will either stop or switch to open-label antidepressants at the discretion of the investigator.